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Hi, I am trying to extract some foreign TV shows and in some rare cases, MakeMKV cannot properly extract PGS subtitles.
The disc have 3 subtitle files and 8 chapters. After extraction and playing in VLC, 2 of the subtitle tracks only shows for the first chapter, with the remaining ~2hrs of content showing no subtitles. However, 1 of the subtitle track shows normally for all 8 chapters.
When playing the disc BDMV directly through VLC, all 3 subtitle tracks shows normally for all chapters.
I tried extracting the SUP files directly from the ripped MKV file and found that 1 of them is significantly larger than the other 2 (150MB vs 19MB vs 18MB)
Is there a specific reason that MakeMKV could not pull the whole subtitle file for particular PGS? I tried just ripping 1 subtitle with the same result
I thought there may be some errors in the read / dump process, but there is no error shown even in debug mode. I tried backing up the disc and decrypting it with the same result
Any suggestions? Thanks

You could try creating a decrypted backup of the disc (on the firs screen of MakeMKV, choose the icon of the yellow folder with the green arrow) and then opening the backup with the MKVToolNix GUI tools. You can create .mkv files from the backup with the MKVToolNix tools. Perhaps it'll create the files with the subtitles as you expect them to be.

Use MakeMKV to create a decrypted copy and demux the subitle files with tsMuxeR. What are the file sizes?